Mapping the proteomes of endoplasmic reticulum domains by proximity biotinylation

The nuclear envelope (NE) acts as a physical barrier which separates the nucleus from the cytoplasm and is involved in numerous biological processes such as gene regulation and repair. It is made up of two lipid bilayers which are continuous with the endoplasmic reticulum (ER) and enclose the chromatin of the cell. Interestingly the inner nuclear membrane (INM), though continuous with the rest of the ER, harbours a distinct set of proteins, and disruption in INM homeostasis has been linked to laminopathies. Early in mitosis, the NE in metazoan cells breaks down and the transmembrane proteins distribute into the ER. After chromosome segregation, the NE envelope is re-established from the ER membrane in the daughter cells. However, the exact mechanism of how INM proteins are able to segregate again from the bulk ER and relocate to the newly formed NE is still poorly understood.
In this project, we aim to investigate the underlying mechanisms of INM protein relocation to the newly formed NE using a combination of techniques including proximity biotinylation, quantitative proteomics and imaging. This research will help us to gain a better understanding of NE formation, INM homeostasis, and will enable us to unravel the mechanisms of how disruption of these processes can result in clinically relevant diseases such as laminopathies.